Error Analysis and Experimental Study of Twelve-branch Orthogonal Parallel Six-axis Force Sensor

Abstract

Six-axis force sensors are widely used in precision fields such as aerospace, robotics, biomechanics and so on. In order to improve the bearing capacity of the sensor and ensure the measurement accuracy, a parallel six-axis force sensor with bidirectional decoupling of tension and compression in orthogonal structure is proposed. By adopting the spherical contact structure as the measuring branch, the sliding friction between the branches of the six-axis force sensor can be changed into rolling friction to reduce the coupling error and improve the accuracy, more suitable for the field of precision measurement. At the same time, according to the force balance equation and the measurement principle of the six-axis force sensor, considering the rolling friction between the branches and the new coupling output error caused by the orthogonal structure, the measurement model of the designed orthogonal structure tension-compression bidirectional decoupling six-axis force sensor is established. Based on the analysis results of numerical examples, the relationship between the coupling error outputs and the corresponding design parameters of the sensor is discussed. Finally, the loading calibration experiment is carried out on the sensor prototype.